In general, when dispensing beverages on drought a keg of beverage feeds one or more taps with beverage via a beverage line by means of a pump or over-pressure so that, when a user opens a tap, beverage is dispensed.
EP-A-1138628 discloses a dispensing apparatus for dispensing a beverage into a receptacle comprising one or more taps between them defining two beverage flow paths. One of the beverage flow paths is provided with a flow restriction for inducing turbulence in the beverage flow, so as to produce foam. The apparatus also comprises means for directing the foamed beverage flow path between 0° and 60° to the horizontal at an outlet, so that fobbing of beverage in the receptacle is prevented.
A problem with known taps, including the one described in relation to EP-A-1138628, is that the speed of dispensation, i.e. the volumetric flow rate of the beverage into the receptacle, may be too slow for dispensing beverages in certain situations. One possible solution to this problem is to use taps having a larger bore and beverage lines having greater internal diameters. However, there is an established infrastructure of beverage lines in outlets, such as public houses. It would, therefore, be extremely costly to upgrade the beverage lines.
Other existing solutions to the aforementioned problems include various methods of increasing the beverage flow rate, for example, by pumping the beverage at greater pressure to the taps. Unfortunately, this particular solution has its own disadvantage, namely, the increased pressure in the line leads to increased fobbing when the beverage is dispensed—which is highly undesirable. Furthermore, such existing solutions tend to be expensive to buy and install the associated equipment, and the equipment takes up valuable space behind the bar.
It will be discerned that the volumetric flow rate of fluid (including a beverage) travelling through a pipe is dependant upon a number of factors, the two most important factors being the internal area of the pipe and the flow rate of the fluid through the pipe. Therefore, the simplest way of increasing volumetric flow rate is to either increase the flow rate or increase the internal area of the pipe. As explained above, neither of these options are readily available to the present situation because of their associated disadvantages and so these parameters are essentially fixed for the beverage dispensing industry. Typical prior art taps provide a significant flow restriction to the beverage to be dispensed. By reducing the flow restriction associated with the tap, volumetric flow rate can be substantially maintained but not increased.
It will also be understood from the general state of the art that faster dispensation of beverage leads to an increased amount of fobbing—which makes the beverage difficult to pour—and gives a head of poor quality. At present, there are no taps which provide a fast dispensation speed, reduce the amount of fobbing and provide a good head.